Methods and systems for precision dosing of fluid systems

Abstract

A method and system to precision dose a fluid system with an injection fluid having chemicals is provided. The method and system includes providing a buffered dosing tank of a known geometry between a source tank and an injection pump. The fluid level detector measures the pressure of the dosing tank to determine a fluid level. The fluid level together with the known geometry allow for a controller to calculate a fluid volume in the dosing tank and a change of volume over time. Using the change of volume over time, the controller can calculate an actual dose rate and adjust a speed or duty cycle of the injection pump such that the actual dose rate is approximately the target dose rate.

1 - 7 . (canceled) 
     
     
         8 . A method of injection chemicals to a fluid system comprising:
 determining a first volume of a dosing tank having a known geometry with injection fluid having a known mixture of injection chemicals;   running an injection pump at a speed/duty cycle to inject the injection fluid into a fluid system configured to receive the injection chemicals at a target dose rate;   stopping the injection of the injection fluid after a period of time;   determining a second volume of the dosing tank;   calculating the volume of injection fluid injected into the fluid system over the period of time;   generating an actual dose rate based on the calculation;   changing the speed/duty cycle of the injection pump based on a comparison of the actual dose rate and the target dose rate.   
     
     
         9 . The method of  claim 8  wherein when the actual dose rate is equal to the target dose rate, the speed/duty cycle of the injection pump is maintained. 
     
     
         10 . The method of  claim 9  wherein when the actual dose rate is greater than the target dose rate, the speed/duty cycle of the injection pump is lowered and wherein when the actual does rate is less than the target dose rate, the speed/duty cycle of the injection pump is risen. 
     
     
         11 . The method of  claim 8  wherein the first volume and the second volume of the dosing tank is determined by detecting dosing tank fluid levels and calculating the first volume and the second volume using the detected dosing tank fluid level and a known geometry of the dosing tank. 
     
     
         12 . A method of filling a dosing tank with injection fluid from a chemical source tank comprising:
 monitoring a fluid level of a dosing tank having a known geometry with wherein the fluid is an injection fluid having a known mixture of injection chemicals;   determining whether the fluid level of the dosing tank is below or equal to a minimum level;   if it is determined the fluid level is below or equal to the minimum level, open a chemical source tank isolation valve such that injection fluid flows from the chemical source tank to the dosing tank;   filling the dosing tank with injection fluid from the chemical source tank;   if it is determined that the fluid level is not below or equal to the minimum level, maintain the chemical source tank isolation valve closed and return to the monitoring step;   determine whether the fluid level in the dosing tank reaches a maximum level;   if it is determined that the fluid level is not at the maximum level, maintain the chemical source tank isolation valve open; and   
       if it is determined that the fluid level is at the maximum level, close the chemical source tank isolation valve. 
     
     
         13 . The method of  claim 12  wherein filling the dosing tank uses gravity to transfer injection fluid from the chemical source tank to the dosing tank. 
     
     
         14 . The method of  claim 12  wherein filling the dosing tank comprises transferring fluid using a fluid transfer pump. 
     
     
         15 . The method of  claim 14  wherein the fluid transfer pump is an injection pump.